Control apparatus



May 11, 1926. 1,584,592

' L. M. ASPINWALL ET AL CONTROL APPARATUS Filed Nov. 5, 1919 3Sheets-Sheet 1 WITNESSES: NVENTORS LouzIS/HASAIHWd &

TORNEY L. M. ASPINWALL ET AL May 11 1926.

CONTROL APPARATUS 1919 5 Sheets-Sheet 2 Filed Nov. 5

w N E V W Laul's MAspzbwa/l & Harg H. [Hg/er ATTORN EY May 11 1926.1,584,592

M. ASPINWALL ET AL,

CONTROL APPARATUS Filed Nov. 5, 1919 3 SheetsSheet 5.

TIER I 47 ii? 55 ,46 in: :1 ---x i Lil-1L1 WITNESSES INVENTORS LouisM/bpmwa Hag/y H. Mg er' W TTORNEY Patented May 11, 19 26.

UNITED STTES ouis M. ASPINWALL, orrrrrsnunen,

AND HARRY R. MEYER, OE WILKINSBURG,

PENNSYLVANIA, ASSIGNOBS TO WESTINGHOUFJE ELECTRIC & MAN UEAGTURING'COMPANY, A CORPORATION OF PENNSYLVANIA.

CONTROL APPARATUS.

Application filed November Our invention relates to control apparatusand it has special relation to the me chanical interlocking of drumcontrollers to prevent false operation.

The object of our invention is to provide a control apparatus embodyinga drum controller and a foot-operated switching device, together withmeans for interlocking the control drum and the switching device toprevent undesirable relative movement of the two members.

More specifically stated, it is an object of our invention to provide aplural-position foot-operated switching device so interlocked with acontrol drum that movement of the drum to an operative position isprevented unless the foot-operated switching device has been opened.

, From another angle, it is an object of our 29 invention to interlockthe above-mentioned control drum and foot-operated switching device sothat the drum may be moved to a dynamic-braking position only when theswitching device occupies an open or inoperative position.

Another object of our invention is to pro vide a quick-operatingmechanism that is associated with the above-mentioned footoperatedswitching device in order to afford relatively rapid closing and openingof the circuit.

Other objects of our invention will be come evident from the followingdetailed description, taken in conjunction with the 35 accompanyingdrawings, wherein Figure 1 is a view, in front elevation, of a controlapparatus constructed in accordance with our present invention;

Fig. 2 is a plan view of a portion of the apparatus that is shown inFig. 1; and

Fig. 3 to 9, inclusive, are detail elevational views illustratingvarious operating members of the apparatus that is shown in thepreceding figures.

Referring to the drawings, the structure here shown comprises a drumcontroller having a rear plate or frame 1 and a curved front cover orencasing member let for en closing a control drum 2 that is providedwith an operating shaft'3, a finger-base 4: for the drum, and afoot-operated switch- 3, 1919. Serial No. 335,492.

ing and interlocking device 5 which is actuated through the agency of apedal mech' anism 6 outside of the controller case.

The lower end of the control drum 2 is supported in asuitable journal 7and a collar 8 is secured to the shaft 3' below the drum 2 for thepurpose of assisting to properly positon the interlocking device 5.

A notched member or star-wheel 9, of a familiar general form, is rigidlysecuredto the operating shaft 3 near its lower end and is provided witha plurality of recesses or notches 10 to 16, inclusive, thatrespectively correspond to the several positions of the control drum 2.The notches 10 and 16, respectively corresponding to the OE and thedynamiobraking positions, are relatively shallow for interlockingpurposesto be setforth, while the remainingnotches are comparativelydeep. The electrical circuits governed by the control drum 2 and thefoot-operated switching device 5 con stitute no part of our presentinvention, but are fully set forth and claimed in a copendingapplication of B. O. Austin, Serial No. 723,847, filed Oct. 6, 1919, andassigned to the Westinghouse Electric & Manufactur ing Company.

Notches 11,12 and 13 thus correspond to forward operation of the motorsto be controlled, while notches 14 and 15 corre spond to reverseoperation. The dynamic-braking notch 16- followsthe reverse notch 15,since the motors necessarily are reversed before dynamic-brakingoperation can be set up, as is Well known.

Loosely enclosing the operating shaft 8,- between the star-wheel 9 andthe collar 8, is a portion of the interlocking device 5 comprising ametallic disk or cam 20, having a hub 20a, and an arm or lever 21 ofbakelized micarta or other similar insulating material which is securedto the disk 20 by means of a plurality of screws 22, One side of the cam20 is provided with a projecting lug 23 and a notch 24- adjacent theretofor interlocking purposes to beset forth. The opposite end of the lever21 has attached thereto, by means of a bolt 25, a bridging contactmember 25a having contact tips 26 and 26a for engaging a pair of spacedstationary contact members 2'? and 27a. The stationary contact membersare suitably secured to bent straps or supports 28 and 2854 which aremounted upon an insulating block 29 that is secured to the plate 1 bymeans of a plurality oi tap bolts 30. F or the purpose or" connectingthe stationary contact members 2'? and 27a to an external circuit, apair of suitable wire-receiving terminals or sockets 81 and are boltedto the supporting members 28 and 28a.

A flat ring 36 (see also Fig. 8 ans Fi 9) of smaller diameter than thedisk 20 is l ly or pivotally fastened, by a small bolt to the switchlever 21. hit a point diametrically opposite the n1cclia;i"--lconnection 37, a boss or stud 38 is located for the purpose of suporting,- one end of a spiral spring 39, the other end or which secured to arocking lever or cranlt arm. 40, which is also shown in Fig. 6 and Fig.*l'. The lower apertured end of the arn'i d0 rigidly attached to a shortshaft 41 that passes through a boss which is secured to the rear plate 1of the controller. A metallic lever or rod 43 is rigidly secured to theouter end of the shaft ll to the rear of the con troller case and ismechanically connected to the pedal mechanism 6, as more fullyhereinafter described.

In order to mutually interlocl; the starwheel 9 and the switch lever 21,whereby undesirable relative movement of the control drum 2 and thefoot-operated switching de vice 5 may be prevented, a pawl member 4e; isprovided, the structural details of which are illustrated in Fig. 3 toFi 5, inclusive.

The pawl ll comprises a base or arm late, upon one end of which a roller45 is loosely mounted for the purpose of ei'igaging the various notches10 to 16, inclusive, in the star-wheel 9. A spacing bl cl: 46 issecured, by rivets 4t6a, to the opposite end oil the arm stale, and aninterlocking); lever l? is located above the block 46, extending atsubstantially right angles to the arm lla, and is held in posit-ion bythe same securing means. A bolt-hole l8 is provided to permit loose orpivotal attachment or" the pawl 4st to a lug 49 upon the inside of therear plate 1 by means of a bolt 49a. A. boss or protuberance 50 on oneedge of the arm ll-a is provided for the purpose of positioning one endof av biasing; spring 51, the other end of which is suitably associatedwith the rear plate 1, whereby the pawl is biased toward a position ofengagement with the notches in the starwheel 9.

For the purpose of biasing the pedal mechanism 6 to a positioncorresponding to the open-circuit condition of the switching device 5, ahelical spring 56, or the equivalent, may be provided. The lower end ofthe spring 56 is hooked through an opening in the rod or lever 43, whilethe upper end of the spring passes over a suitable boss or lug 58 on theoutside of the rear plate 1. The tree end 59 of the lever l3 is slottedto engage one end of a. linl: or clcvis 20, whereby a suitablelost-motion connection is provided let-ween the lever 4-3 and the pedalmechanism (5. The mechanism (5 is shown as comprising a pedal ortoot-lever G1 which has a detachable hook connection (52 with one end ofthe link or clevis 60, and the underside of the pedal 61 is providedwith a pair 01. depending lugs or arms 23 for partially enclosing a pinor pivot G The pin (ll: is supported by a pair of standards or brackets66 that are integrally associated with a suitable base 67. A. pluralityof bolts 68 may be employed to secure the base 6? in he desiredlocation. By reason of the illusrated pivotal construction oi": thepedal 61, the pedal may be removed, when desired, io," operation at theother end of the vehicle d to prevent unauthorized moven'ient ot hemechanism.

he control drum 2 cu pving is illustrated as ocinitial position in theforward direction or, in other words, the roller of the pawl -l-l-.engages the notch 11 while the iioot-operatod switching device 5 isshown as occupying its closed position, wherein the contactl'l'lOllllJQlS 26 and 27, for example, a re in engagement The operationof our controlling and interlocking device, under such conditions, maybe set forth as follows. It it i attempted to move the control drum 2bacliwardly to the oil position, corresponding to the engagement ofroller and notch 10, such act-ion cannot be ellectcrl so long as thefoot-operated switching device 5 remains closed, since the roller 45cannot pass over the ridge between the notches 11 and 10 by reason ofthe fact that the interlocking arm ct? strikes the adjacent portion ofthe switch. cam 20. Consequently, the control drum 1 cannot be returnedto its oil? position until the pedal mechanism (3 is released by theoperator removing his foot, whereupon, the spring 56 will return theconnected members to their normal or biased positions and, inparticular, the short shaft 41 and the crank arm 40 will be rotatedclockwise. As soon as the line of action or the spring 39 passes beyondthe deadcenter position, with respect to the switch arm 21, namely,beyond a line i 11;); through the pivotal point 37 and the axis of theoperating shaft 3, the toot-operated switching device will be quicklyopened. The extreme open position of the switching device 5 isdetermined by the engagementot the lug 23 on the switch arm 21 with theinterlocking pawl arm 47. In that case, the desired backward movement ofthe control drum 2 may be effected.

lVhen the control drum 2 is moved to its off position corresponding tothe engagement of roller 45 and notch 10, the switching device 5 beingopen, the pawl arm 44a is actuated in opposition to the co l spring 51-,and the interlocking arm 47 is rotated clockwise, when viewed fromabove, being guided, by the lug 23, into a position of engagement withthe notch 24 in the switch cam 20. Consequently, movemen of theswitching device 5 into its illustrated operative position is prevented,since the cam 20 cannot be moved so long as the interlocking arm 47engages the notch 24. However, the control drum may be moved to anyother position to set up the; desired motor connections. In that case,unless the dynamic-braklng position, corresponding to shallow notch 16,has been selected, the foot-operated switching device may be closed asfollows. Upon the application of clownward pressure to the toe of thepedal 61, the lever arm 43 is depressed in opposition to the action ofthe biasing spring 56, the shaft 41 and the crank arm 40 are rotated ina counter-clockwise direction, and the. switching device 5 is quicklyactuated to its illustrated closed position as soon as the line ofaction of the spring 39 passes beyond the above-mentioned dead-centerposition.

Consequently, the mechanical interlocking that we provide prevents thecontrol drum 2 from either opening or closing the electric circuit, andall. such making and breaking of the circuit is accomplished by thefoot-operated switching device 5.

Further interlocking of the control drum and the foot-operated switchingdevice is rovided in the dynamic-braking position of the control drum,corresponding to shallow notch 16. It will be appreciated that, wheneverthe motor circuits are to be re organized for dynamic braking, theconnection of the motors to the supply circuit should be maintainedopen. This function is assured by the operation of our mechanism, sincethe roller 45 of the pawl 44 cannot pass over the ridge between notches15 and 16 when the switching device occupies its illustrated closedposition, because, in that case, the interlocking arm 47 engages theadjacent portion of the switch cam 20 and the attempted rotativemovement of the control drum is precluded. However, upon release of thepedal mechanism 6 to effect the above-mentioned quick-opening move mentof the switching device 5, the interlocking arm 47 is then locatedopposite the peripheral notch 24 in the switch cam 20 and, therefore,movement of the control drum to its dynamic-braking position,corresponding to the engagement of roller 45 and notch 16, is permitted.In this way, dynamicbraking circuits cannot be set up unless the line orsupply-circuit connection of the motors has previously been interrupted.

In other words, the footope'rated switch ing device 5 cannot be closedwhen the control drum occupies either its off or its dynamicbrakingposition, since the interlocking arm 47 is prevented from clearing thenotch 24 by'reason of the provision of the shallow notches 10 and 16 inthe starwheel 9.

edo not wish to be restricted to the specific structural details orarrangement of parts herein set forth, as various modifications thereofmay be made without departing from the spirit and scope of ourinvention. WVe desire, therefore, that only such limitationsshall beimposed thereon as are indicated in the appended claims.

lVe claim as our invention:

1. Control apparatus comprising two transversely-related shafts, aswitch member and a star-wheel respectively loosely and rigidly mountedon one of said shafts, a crank arm rigidly secured to the other shaft,an interlocking pawl between said star-wheel and said switch member, anda flexible connection between said switch member and said crank arm,

2. Control apparatus comprising two transversely-re1ated shafts, aswitch member and a star-wheel respectively loosely and rigidly mountedon one of said shafts, a crank arm rigidly secured to the other shaft,an interlocking pawl between said star-wheel and said switch member, aring enclosing one of said shafts and having one point loosely securedto said switch member, and a spring for connecting a diametricallyopposite point in said ring to said crank arm.

3. In a controller, in combination, a drum shaft, a star wheel mountedon the shaft, a switch member loosely mounted on said shaft and disposedfor movement relative to the star wheel, means for actuating the switchmember independently of the star wheel, a spring-pressed pawl interposedbetween the star wheel and switch member, said star wheel being adaptedwhen moved to a predetermined position to actuate the pawl to lock theswitch member.

4. In a controller, in combination, a drum shaft, a star wheel mountedon the shaft, a switch member loosely mounted on said shaft and disposedfor movement relative to the star wheel, means for actuating the switchmember independently of the star wheel, a spring-pressed pawl interposedbetween the star wheel and switch member, said switch member and starwheel being adapted to cooperate when in predetermined positions torestrict the movement of one another, and means adapted to limit,independently of the star wheel, the operation of the switch rmember inone direction.

5. In a controller, in combination, a drum shaft, a star wheel mountedon the shaft, a switch member loosely mounted on said shaft and disposedfor movement relative to the star wheel, means for actuating the switchmemher independently of the star wheel, a spring pressed pawl interposedbetween the star wheel and switch member, the switch member having anotch therein to receive an end of the pawl, said star wheel beingprovided with a projection adapted to actuate the pawl to engage in saidnotch, thereby to lock the switch member.

6. In a controller, in combination, a drum shaft, a star wheel fixed tosaid shaft, a switch member loosely mounted on said shaft and rotatablymounted on the shaft, means for actuating the switch memberindependently of the star wheel, a springpressed pawl interposed betweenthe star wheel and the switch member, the spring serving to retain thepawl continuously in engagement with the star wheel, said switch memberhaving a notch therein to receive one end of the pawl, an indentedprojection formed on the star wheel for operating the pawl to engage inthe notch to lock the switch member and means carried by the switchcooperative to limit its angular movement in one direction.

In testimony whereof, we have hereunto subscribed our names this 27thday of Oct, 1919.

LOUIS M. ASPINWALL. HARRY R. MEYER.

